Plasma TMAO: increased by 3- and 4-repeated cerebral ischemia reperfusion, decreased by baicalin, correlated with behavioral and electrophysiological deficitsCognition (novel object recognition and Morris water maze): cognition improved by baicalin can be diminished with broad spectrum antibioticsHippocampus: the reduction in Nissl bodies, dendritic spine density, and synaptic proteins, the higher levels of IL-1β, IL-6, and TNF-α after repeated cerebral ischemia-reperfusion can be restored by baicalin. The gene discussed is TNF; the disease is brain ischemia.